How VFDs can make manufacturing more sustainable

Variable frequency drives (VFDs) are playing a key role in helping manufacturers adopt more sustainable practices.

By Owain Betts November 9, 2023
Courtesy: Control Engineering Europe, Invertek

With environmental concerns and climate change at the forefront of global priorities today, manufacturers are under increasing pressure to adopt more sustainable practices.

Reducing energy consumption and its associated harmful emissions have become critical objectives for organizations worldwide, including the UK and Europe, where various governmental targets and regulations are already in place.

While many are calling for the development of new, cutting-edge technologies to address these challenges, one proven solution already exists in the form of variable frequency drives (VFDs)

It is believed around 80% of electric motors in the world are still not controlled by a VFD. That means they are working constantly, inefficiently, and are wasting energy. Indeed, most motion-controlled applications use an electric motor – conveyors, lifts, fans, pumps, mixers – the list is almost endless. Companies can benefit financially by reducing their environmental impact through lower energy costs.

Four impacts of not using VFDs

The impact of not using VFDs are many, including the following:

  1. Higher energy consumption: Electric motors without VFDs typically run at a constant speed, which can result in higher energy consumption. This constant-speed operation is often unnecessary because many applications have varying load requirements. Without VFDs to adjust motor speed according to demand, energy is wasted during periods of lower load.

  2. Increased emissions: The increased energy consumption associated with constant-speed Direct on-line (DOL) electric motors contributes to higher greenhouse gas emissions. More energy is required to operate these motors and if the electricity generation is not primarily from clean, renewable sources, it will lead to a higher carbon footprint.

  3. Reduced efficiency: Operating motors at a fixed speed can lead to inefficiencies in processes. For example, pumps, fans, and conveyors that do not adjust their speed to match the required output may experience excess wear and tear and increased maintenance costs.

  4. Higher operational costs: Businesses and industries that rely on electric motors without VFDs may experience higher operational costs due to increased energy bills and maintenance expenses.

What are VFDs?

A VFD is an electronic device that controls the speed and torque of an electric motor by adjusting the frequency and voltage supplied to it. In effect, VFDs provide precise control over motor speed, allowing for optimal performance in various industrial applications.

VFDs are sophisticated yet adaptable tools that play a pivotal role in energy efficiency, making them a useful tool for manufacturers seeking to minimize their environmental footprint.

In addition, they can reduce wear and tear by extending the lifespan of equipment by reducing mechanical stress. Smooth starts and stops, along with the ability to adjust speed as needed, result in less wear and tear on motors and associated components.

One Italian industrial automation control systems supplier, for example, has significantly cut energy and maintenance costs in the use of an industrial shredder by introducing a VFD into its process.

High electrical absorption was being created on start-up by an existing star/delta starter. This, combined with a lack of motor speed control, was creating high energy costs and wear on the blades of the shredder. The motor control was a particular issue as this meant the speed of the cutting blades couldn’t be adjusted to match the type of material being shredded. This resulted in wear and damage to the blades. As a result, they needed to be regularly repaired or replaced.

The decision was made to change the existing main line fed Star/Delta starter for a VFD. Straight away it was possible to accurately control the speed of the motor, resulting in reduced energy use. A range of materials were shredded and there was immediately much less wear or damage. Importantly, the previous high absorption resulting from star/delta starter was reduced, cutting energy costs for the plant.

As the world grapples with the urgent need to reduce energy consumption and curb harmful emissions, VFD technology is a technology that is already here and can make a difference today. It is not a futuristic concept but a practical, readily available solution that can empower manufacturers to operate more sustainably and efficiently.

– This originally appeared on Control Engineering Europe’s website.

Author Bio: Owain Betts is communications manager at Invertek Drives.